SaikoTroid

Changing the escape/command character in GNU Screen

2012-02-11T08:31:00.000-08:00

Using Colourlovers.com API with NodeJS

2012-02-11T08:10:00.000-08:00

Colourlovers.com has a pretty good and straightforward API.

The following snippet fetches the top palettes with the help of NodeJS

Customizing The Mongodb Interactive Shell

2012-01-30T20:00:00.000-08:00

When the shell is launched, it checks the user's home directory for a javascript file named .mongorc.js.
If this file is found, its contents are interpreted and run by the shell prior to displaying the prompt for the first time.
This allows the user to define variables, customize the prompt, or update information that they would like updated every time they launch a shell.

Here is my .mongorc.js

Show file history in git

2012-01-24T22:15:00.000-08:00

There are two amazing tools to show a history of a file in git.

gitk /path/of/file
or
tig /path/of/file

Google Chrome 'Confirm to Quit' on Lion

2012-01-21T01:01:00.000-08:00

To avoid accidentally closing the browser, executing this line in Terminal makes Google Chrome require
Shift + Cmd + Q to quit.

localStorage in iOS5 Private Browsing mode

2012-01-19T23:05:00.000-08:00

Attempting to use localStorage.setItem in iOS5 Private Browsing mode will throw the exception

QUOTA_EXCEEDED_ERRROR DOM Exception 22.

But getItem and removeItem calls do not throw.

You can see some details about that in the jStorage discussion

Font smoothing on Webkit

2012-01-16T07:42:00.000-08:00

I’m not a big fan of the default text rendering in WebKit, it looks heavy. Fortunately there is a solution.

You can find here more examples on Christoph Zillgen's site.

Gitignore for an iPhone (XCode) project

2012-01-11T03:39:00.000-08:00

File changes since last week in a git repo

2012-01-09T21:39:00.000-08:00

Sluggish scroll in MacVim

2012-01-06T23:39:00.000-08:00

There can be several reasons for sluggish scroll.
For me setting up 'ttyfast' solved the problem.

Delete all trailing whitespace in VIM

2012-01-06T20:18:00.000-08:00

You can find more information about VIM and whitespaces here

Remove app from sale in iTunes Connect

2012-01-06T03:52:00.000-08:00

It is not trivial.

1. Select your app

2. Click on Rights and Pricing

3. There is a link 'Unless you select specific stores, your app will be for sale in all App Stores worldwide.', click on the 'specific stores'

4. Deselect all locations

5. Save

Now, after removing the app form sale, you can remove it.

Favorite startup books on Audible

2011-12-25T07:12:00.001-08:00

I'm a big fan of Audible.com, here are my favorites and my wish list.

The Lean Startup: How Today's Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses.
by Eric Ries

Positioning: The Battle for Your Mind
by Al Ries , Jack Trout

Differentiate or Die
by Jack Trout , Steve Rivkin

The 22 Immutable Laws of Marketing
by Al Ries , Jack Trout

A Whole New Mind: Why Right-Brainers Will Rule the Future
by Daniel Pink

Drive: The Surprising Truth about What Motivates Us
by Daniel Pink

Rework
by Jason Fried , David Heinemeier Hansson

Dot.Bomb
by J. David Kuo

The New New Thing: A Silicon Valley Story
by Michael Lewis

The Anatomy of Buzz
by Emanuel Rosen

The Search: How Google & Its Rivals Rewrote the Rules of Business & Transformed Our Culture
by John Battelle

How to Win Friends & Influence People
by Dale Carnegie

The Tipping Point: How Little Things Can Make a Big Difference
by Malcolm Gladwell

The Innovator's Solution: Creating and Sustaining Successful Growth
by Clayton M. Christensen , Michael E. Raynor

If you need more books you can follow Joel Spolsky's list.

Bash script can tell its location

2011-12-23T00:15:00.000-08:00

You can get the path of the directory in which a bash script is located FROM that bash script.

Read more about this problem on stackoverflow.

Loading an agent on OSX

2011-12-22T00:24:00.000-08:00

Print out more than 20 items in mongodb shell

2011-12-20T19:28:00.000-08:00

When you're listing a large dataset in the shell you'll only see 20 items by default and a 'has more' text indicating that there are more.
If you want to change this limit you can use


DBQuery.shellBatchSize = 300

in the shell.

Loading CDN hosted jQuery with local fallback

2011-12-17T19:34:00.000-08:00

I found this piece of art in html5boilerplate.
It tries to load jQuery from a CDN and if it fails for whatever reason it tries a local one.

Replace line break with comma in bash

2011-12-12T19:55:00.000-08:00

Creating a custom google maps marker with canvas

2011-12-09T07:25:00.000-08:00

Generating a custom marker with canvas is handy when you want to change the marker size/color dynamically.

The following code snippet contains a 'createMarker' function that creates a canvas, draws the marker graphics and returns back the Data URL encoded version of that canvas which can be used as an input at the marker creation.

See the example below.

String trimming in Javascript

2011-11-03T03:52:00.000-07:00

Here is a simple trim function to remove leading and trailing whitespaces.


function trim(s) {
  return s.replace(/^\s*|\s*$/g, '');
}

and in CoffeeScript

trim = (s) ->
  s.replace /^\s*|\s*$/g, ''

You can check Steven Levithan's collection of trim functions.

'Taglist: Exuberant ctags (http://ctags.sf.net) not found in PATH. Plugin is not loaded.' error in MacVim (Janus)

2011-10-29T06:43:00.000-07:00

After launching MacVim you may get this annoying error message:
'Taglist: Exuberant ctags (http://ctags.sf.net) not found in PATH. Plugin is not loaded.'

To remove this you have to install ctags which you can download from http://ctags.sf.net.
After you unziped it, you have to set the Tlist_Ctags_Cmd variable in the .vimrc file to point to the ctags folder.


let Tlist_Ctags_Cmd = '/usr/local/bin/ctags'

After that you have to restart vim and the message should not pop up again.

Launching MacVim from Command line

2011-10-25T08:21:00.001-07:00

Put this into your .profile or .zshrc file
function mvim { /Applications/MacVim.app/Contents/MacOS/Vim -g $*; }
Then you can use 'mvim' in the command line.

The full explanation is in the MacVim Google Groups

Simulating slow network connection in OSX

2011-09-27T23:33:00.000-07:00

Setup
sudo ipfw pipe 1 config bw 16Kbit/s delay 350ms

sudo ipfw add 1 pipe 1 src-port 80
sudo ipfw add 2 pipe 1 dst-port 80

Remove
sudo ipfw delete 1
sudo ipfw delete 2

sudo ipfw pipe 1 delete

Disable spotlight

2011-09-21T04:00:00.000-07:00

Disable Spotlight
sudo mdutil -a -i off

Enable Spotlight
sudo mdutil -a -i on

Tapping on in Mobile Safari

2011-09-20T01:41:00.000-07:00

Tapping on <label> does not auto-focus linked in Mobile Safari but If we add an empty function as clickhandler it works fine.


<input type="checkbox" id="test" name="test">
<label for="test" id="test_label">This is the label</label>
<script>
  document.getElementById("test_label").onclick = function () {};
</script>

This is the releated Stackoverflow discussion.

Checkbox/Radio button size on Android Safari

2011-09-08T00:55:00.001-07:00

You cannot change checkbox/radio button width/height on Android in Safari because it is tied to the OS.

But since the default ones are so tiny that you may need bigger buttons.
Here is a simple trick:


input[type=checkbox] {
  -webkit-transform: scale(2,2);
}

Please note that if you set up values bigger than ~2 then the yellow outline will look weird.

Get links from a page with bash

2011-07-29T01:50:00.000-07:00

Get anchor elements from a webpage can be done with

curl URL 2>&1 | grep -o -E 'href="([^"#]+)"' | cut -d'"' -f2

where you replace URL with your choice, just like here:

curl http://cookpad.com 2>&1 | grep -o -E 'href="([^"#]+)"' | cut -d'"' -f2

Switching back to the previous application with AppleScript

2011-07-26T23:07:00.001-07:00

If you want to simulate cmd + tab with AppleScript, here it is


tell application "System Events"
  tell process "finder"
    activate
    keystroke tab using {command down}
  end tell
end tell

You can use the same thing in bash


echo 'tell application "System Events"
  tell process "finder"
    activate
    keystroke tab using {command down}
  end tell
end tell' | osascript

Show Git Commits By Author

2011-07-14T01:16:00.001-07:00

It is as simply as

git log --author=<PATTERN>

for example


git log --author=viktor

Resize and position windows with AppleScript

2011-07-05T22:25:00.000-07:00


-- get the dimensions of the desktop, set up few variables
tell application "Finder"
 set displayAreaDimensions to bounds of window of desktop
 set x1 to item 1 of displayAreaDimensions
 set y1 to item 2 of displayAreaDimensions
 set x2 to item 3 of displayAreaDimensions
 set y2 to item 4 of displayAreaDimensions
end tell

set width to x2 - x1
set height to y2 - y1

-- positioning iTunes, make it fullscreen
tell application "iTunes"
 set the bounds of the first window to {x1, y1, x2, y2}
end tell

-- positioning Safari, halfwidth on the right
tell application "Safari"
 set the bounds of the first window to {x1 + width / 2, y1, x2, y2}
end tell

-- positioning iTerm
tell application "iTerm"
 set the bounds of the first window to {x1, y1, x1 + 1000, y1 + 600}
end tell

There are few useful blogposts about the topic.
www.ithug.com/2007/09/applescript-moving-and-resizing-windows or
www.ithug.com/2008/12/applescript-arranging-multiple-windows/

or you can use Divvy, which is an amazing window management app.

Generating QR Codes with Google

2011-07-05T07:40:00.000-07:00

The google chart API has this feature.


http://chart.apis.google.com/chart?cht=qr&chl="+[YOUR_TEXT]+"&chs=[XSIZE]x[YSIZE]"

For instance


http://chart.apis.google.com/chart?cht=qr&chl="Hello World"&chs=120x120"

will generate this

Changing the default google domain in Chrome

2011-06-30T19:53:00.000-07:00

On a mac, make sure that you closed the Chrome browser.

Go to


cd ~/Library/Application\ Support/Google/Chrome

and edit the 'Local State' file,
change the following lines to whatever google domain you want.


"last_known_google_url": "http://www.google.com/",    
"last_prompted_google_url": "http://www.google.com/",

start the browser.

If you use profiles you have to go to that profile folder and change the 'Local State' file there


cd ~/Library/Application\ Support/Google/Chrome/[PROFILE NAME]

Application Cache whitelisting the master entry

2011-06-30T09:09:00.000-07:00

An application cache is a set of cached resources consisting of:

Master entries
These are documents that were added to the cache because a browsing context was navigated to that document and the document indicated that this was its cache, using the manifest attribute.

Explicit entries
These are the resources that were listed in the cache's manifest in an
explicit section (CACHE).

Fallback entries
These are the resources that were listed in the cache's manifest in a fallback section.

The resource that declares the manifest (with the manifest attribute) will always get taken from the cache, whether it is listed in the cache or not, even if it is listed in an online whitelist namespace.
This means that your HTML that includes the manifest file will be always a master entry which is cached and accessed from the cache even the client is online.
Let's face it, this is a pain in the neck in same cases.

There is a simple workaround
1. create an OTHER HTML that will include the manifest file
2. from the ORIGINAL HTML remove the manifest include and create an iframe that includes the OTHER HTML

In this case the master entry will be this OTHER HTML, which does not affect whitelisting the ORIGINAL HTML.

I'd like to emphases that this is just a workaround and i'd like to have a better solution.

You can also follow the related whatwg discussion.

Migrating to Dotcloud CLI 0.4.x with 'pip: error: no such option: -u'

2011-06-28T08:45:00.000-07:00

Checking the version number


$ dotcloud --version
DotCloud CLI version 0.3.1

Installing Pip (it is a tool for installing and managing Python packages)


$ sudo easy_install pip

Installing the dotcloud CLI 0.4.x


$ sudo pip install --upgrade dotcloud

In the dotcloud migration document they use pip -U but in Pip version 1.0.1 there is no such an option.

Checking the version number again.


$ dotcloud --version
DotCloud CLI version 0.4.0

All right.

Image width/height with Imagemagick in Command line

2011-06-24T00:59:00.000-07:00

Imagemagick comes handy when you need information from an image.


# width
w=`identify -format "%w" image.png`

# height
h=`identify -format "%h" image.png`

More information on Imagemagick's identify.

URL shortener algorithm

2011-06-03T08:39:00.000-07:00

I have a database table with three columns:

1. id, integer, auto-increment
2. long, string, the long URL the user entered
3. short, string, the shortened URL (or just the six characters)
I would then insert the long URL into the table. Then I would select the auto-increment value for "id" and build a hash of it. This hash should then be inserted as "short". But what sort of hash should I build?

We've to convert a string (id converted into a string) that uses [0-9] alphabet into a string that uses [a-zA-Z0-9].


var codeset = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
var base = codeset.length;

function encode(n) {

 var converted = "";

 while (n > 0) {
   converted = converted + codeset[n%base];
   n = Math.floor(n/base);
 }

 return converted;
}

and


function decode(converted) {

 var c = 0, ind;

 for (var i = converted.length-1; i >= 0; i--) {
  c += (codeset.indexOf(converted[i])) * Math.pow(base, i);
 }

 return c;
}


console.log("Test #1: ", 125 == decode(encode(125)));

more on that on stackoverflow or on snook.ca

useful iterm2 shortcuts

2011-05-30T23:25:00.000-07:00

iTerm2 is a good replacement for Terminal on OS X

Splitting the window: Command+D to split the window vertically, or Command+Shift+D to split the window horizontally.

Switching between the sub-windows: Command+[ or Command+] or Command+Opt+arrows

Fullscreen: Command+Enter

req.body undefined in POST request in Express js

2011-05-21T05:49:00.000-07:00

You have to use a bodyparser to process the body of a POST request

app.use(express.bodyParser());

and put this before the routing definition, like this


app.configure('development', function() {

 console.log("Development mode");

 app.configure(function() {
    app.use(express.bodyParser());
    app.use(app.router);
    .....
 });
});

here is the related google groups thread.

bash history

2011-05-15T18:35:00.000-07:00

Bash history preserved in ~/.bash_history there are a few ways to search it.

history | grep

history | grep git

the output would be like that


475  git checkout -f
479  gitx
481  git co sp/sprint1
487  git co master
488  git branch -D sp/sprint1
489  git br
491  git co sp/sprint1
496  git diff | gitx
502  git st
510  history | grep git

the followings will reference to line '502 git st'


> !502

# counting back from the last one
> !-1

# same as !-1
> !!

using the last event starting with 'git'
> !git

Or press Ctrl-R, and as you start typing the search goes back in reverse order to the first command that matches the letters you’ve typed.

Once you’ve found the command you have several options:

- Run it verbatim – just press Enter
- Cycle through other commands that match the letters you’ve typed – press Ctrl-R successively
- Quit the search and back to the command line empty-handed – press Ctrl-G

if you're using the history a lot you may want to add these line to your bash init file (~/.bash_profile)


# remove duplicates from the history
export HISTCONTROL=erasedups

# increases the history size
export HISTSIZE=10000

# ensures that when you exit a shell, the history from the session is appended to bash_history
shopt -s histappend

I copy and pasted from the following articles
working-with-history-in-bash, bash-history-reverse-intelligent-search, man history

i like Bash a lot.

top commiters on a git branch

2011-05-15T18:32:00.000-07:00

You want to have a list of contributors sorted by number of commits?


git log --format=format:%an | sort | uniq -c | sort -r

will output something like that


1081 Mito
1033 sudo
872 Yusuke
478 morita
423 Yuki
396 Takahiro

Sniffing Android Tablets

2011-05-08T21:09:00.001-07:00

On Android devices the "Mobile" string in the User Agent indicates that the device would prefer a version of the website optimized for Mobile (small form factor devices).
Tablets don't have this, for example


Mozilla/5.0 (Linux; U; Android 2.2.1; en-us; device Build/FRG83) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Safari/533.1

unlike phones


Mozilla/5.0 (Linux; U; Android 2.2.1; en-us; Nexus One Build/FRG83) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1

This can be used to detect Android tablet devices


is_androidmobile = request.user_agent =~ /android/i && request.user_agent =~ /mobile/i

in context


def is_mobile?
    is_iosmobile = request.user_agent =~ /iphone|ipod/i
    is_androidmobile = request.user_agent =~ /android/i && request.user_agent =~ /mobile/i

    return is_iosmobile || is_androidmobile
end

more on that here,
android-browser-user-agent-issues

my ~/.gitconfig file

2011-04-26T20:14:00.000-07:00

[user]
    name = Viktor Kelemen

[color]
    diff = auto
    status = auto
    branch = auto
    interactive = auto
    ui = true
    pager = true

[color "status"]
    added = yellow
    changed = green
    untracked = cyan

[core]
    pager = less -FRSX
    whitespace=fix,-indent-with-non-tab,trailing-space,cr-at-eol

[alias]
    co = checkout
    st = status
    ci = commit
    co = checkout
    w = whatchanged
 lg = log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit --date=relative

You can find more about .gitconfig customization on Hackernews or on Stackoverflow

Get HTTP status code with curl in bash

2011-04-21T22:33:00.000-07:00


curl --write-out %{http_code} --silent --output /dev/null URL

and then wrapping it into a function


getHTTPCode () {
    echo $(curl --write-out %{http_code} --silent --output /dev/null $1)
}


response=$(getHTTPCode URL)
echo $response

Failed to install db46 on Snow Leopard

2011-04-18T22:07:00.000-07:00

I have a brand new macbook (2011/04/19) and have some trouble with installing db46 with ports


port install db46

fails badly and complains about dependencies.

The easiest fix is to install it without java (and you don't need java)


sudo port -v selfupdate
port clean db46
port install db46 +no_java

There are other articles about this problem, How to fix db46 problem macport installation
or MacPorts 1.8.2 fails to build db46 on Mac OS X 1.6.3

Joyent Smartmachine Nodejs log

2011-04-15T23:48:00.001-07:00


tail -f /var/svc/log/site-node-service\:default.log

Reset Joyent Smartmachine Nodejs git repo

2011-04-14T04:30:00.000-07:00


cd ~
rm -rf repo
mkdir repo
cd repo
git --bare init
cp /opt/nodejs/post-receive* hooks/
cd ~

Deleting the old repo, creating a new one and then copy the post-recieve hooks.

Turning off case-sensitive tab completion in bash

2011-03-26T03:36:00.000-07:00

/etc/inputrc deals with the mapping of the keyboard for certain situations.

Adding


set completion-ignore-case on

to the file turns off case-sensitivity in tab completion.


echo set completion-ignore-case on | sudo tee -a /etc/inputrc

Disable the text-highlighting magnifier on touch-hold on Mobile Safari / Webkit

2011-03-10T07:07:00.001-08:00

<style>
 * {
      -webkit-user-select: none;
}
</style>

Building Xcode Projects From the Command Line

2011-03-05T23:50:00.001-08:00

xcodebuild -project myProject.xcodeproj -alltargets

md5sum on Snow Leopard

2011-03-05T05:18:00.000-08:00

The MD5 hash (or checksum) functions as a compact digital fingerprint of a file.

You can check the md5 hash of a file with the md5 command
md5 test.txt

The output looks like this
MD5 (test.txt) = ab41fdba223f971be13b1845122353cb

Dropbox as a git repo

2011-03-01T18:23:00.000-08:00

In your Dropbox folder


mkdir Repositories
cd Repositories
mkdir myNewProject.git
cd myNewProject.git
git init --bare

In your project


cd ~/workspace/MyNewProject
git remote add origin ~/Dropbox/Repositories/myNewProject.git
git push origin master

more on this topic, using-gitdropbox-together-effectively or How to use Dropbox as a git repository

Supervisor for NodeJS

2011-02-28T23:03:00.000-08:00

Supervisor runs your nodejs programs and restarts them when a *.js file changes


npm install supervisor


supervisor -p server.js -w .

This example runs server.js and watches the current folder, if a js file changes in this folder it restarts the server.js

Installing NodeJS from source on Snow Leopard

2011-02-28T22:43:00.000-08:00


git clone https://github.com/joyent/node.git
cd node

mkdir ~/local
./configure --prefix=$HOME/local/node
make
make install
export PATH=$HOME/local/node/bin:$PATH

Now if you open a new terminal window


node --version

you should see the new version number.

Get page response time with bash

2011-02-28T19:57:00.000-08:00


(time curl URL --head) 2>&1 | grep real | cut -c 6-

for instance


(time curl http://google.com --head) 2>&1 | grep real | cut -c 6-

the response is something like this
0m0.072s

CoffeeScript Syntax Checker Textmate Bundle

2011-02-13T07:47:00.000-08:00

Here is a rudimentary version of my CoffeeScript bundle that performs a quick syntax check.
You can bind this command to CMD + S, so it runs after save.

CoffeeScript-Syntax-Checker-Textmate-Bundle on Github

Building CoffeeScript from source

2011-02-13T05:01:00.000-08:00

CoffeeScript includes a simple build system similar to Make and Rake. Naturally, it's called Cake, and is used for the build and test tasks for the CoffeeScript language itself.


git clone https://github.com/jashkenas/coffee-script.git
cd coffee-script

To build the whole system


bin/cake build:full

To build the script for inclusion in the browser


bin/cake build:browser


MINIFY=false bin/cake build:browser

you may need to install uglify-js as well
npm install uglify-js

Infinite webkit keyframe animation

2011-02-11T08:05:00.000-08:00

Here is a simple example of an infinite animation.

<head>
    <style>
        @-webkit-keyframes infinite-spinning {
            from {
                -webkit-transform: rotate(0deg);
            }
            to {
                -webkit-transform: rotate(360deg);
            }
        }

        #box {
             -webkit-animation-name: infinite-spinning;
             -webkit-animation-duration: 1s;
             -webkit-animation-iteration-count: infinite;
             -webkit-animation-timing-function: linear;
             width: 100px;
             height: 100px;
             background: #00f;
        }  
    </style>
</head>
<body>
    <div id="box">
    </div>
</body>

Janus vs 'unable to determine script type'

2011-02-10T21:58:00.000-08:00

Update 2011/02/14
Janus developers pulled my changes so if you checkout the latest code you won't see this problem.

Janus is a basic distribution of vim plugins and tools intended to be run on top of the latest MacVIM snapshot.

I tried to install it today but i got this 'unable to determine script type' error

I opened the Rakefile and figured out that the problem is that the vim.org/scripts does not response.

I looked for mirrors and found one on github, git://github.com/vim-scripts/
I replaced all the vim.org lines with github.com/vim-scripts, it seems working now.

Here is the diff for the Rakefile

Get folder size on OSX

2011-02-09T23:53:00.000-08:00

Haruka had this problem, here is a simple solution
du -sh FOLDER_NAME

du (abbreviated from disk usage) is a standard Unix program used to estimate the file space usage—space used under a particular directory or files on a file system.

You want to attend GoogleIO 2011?

2011-02-08T17:49:00.000-08:00

I'm sorry, but you cant!
It was sold out in the first hour after the registration
opened.

Good luck in 2012 ;)

The good news is that the GoogleIO 2011 will be live-streamed and the videos will be available from the WebSite later.
Stay tuned!

Customized google maps

2011-02-07T23:56:00.000-08:00

You change the look and feel of google maps easily.

Here is a simple example that turns off all labels on the map


map = new google.maps.Map(mapContainer, {}));

var noLabelStyle = new google.maps.StyledMapType([ {
        featureType: "all",
        elementType: "labels",
        stylers: [
            { visibility: "off" }
        ]
    }], {
        name: "no_labels_style"
    });

map.mapTypes.set('stylename', noLabelStyle);
map.setMapTypeId('stylename');

The most important part is the google.maps.StyledMapType class.
Its constructor expects an array, and that describes which element should be visible and how.

You can find the details documentation in the API reference.

Editing files in the user's path

2011-02-07T22:12:00.001-08:00

I have lots of scripts in my path but the actual location differs.

If i have to edit them i often do
vim `which FILE_NAME`

for example
vim `which port_utility`

The which utility takes a command name and searches the path for each executable file that would be run had this commands actually been invoke.

Apache on Snow Leopard, "ulimit: open files: cannot modify limit: Invalid argument"

2011-02-07T21:54:00.000-08:00

When I started apache on my Snow Leopard i got a weird exception

/usr/sbin/apachectl: line 82: ulimit: open files: cannot modify limit: Invalid argument

So I opened the script and found that there is something wrong with $ULIMIT_MAX_FILES

The error message says that 'cannot modify limit' so i changed its value to empty string


# ULIMIT_MAX_FILES="ulimit -S -n `ulimit -H -n`"
ULIMIT_MAX_FILES=""

Voila, it works, but deeper investigation need.

Base64 encoding

2011-02-07T19:16:00.000-08:00

Base64 is a group of similar encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation.
Base64 encoding schemes are commonly used when there is a need to encode binary data that needs be stored and transferred over media that are designed to deal with textual data.

to encode

openssl base64 -in INPUT_FILE -out OUTPUT_FILE

and to decode from Base64:

openssl base64 -d -in INPUT_FILE -out OUTPUT_FILE

Email filtering with Sieve

2011-02-06T19:48:00.000-08:00

Sieve is a programming language that can be used to create filters for email.

I use Sieve to manage my emails on the company's IMAP server.


require "fileinto";

if address :is "From" "support@company.jp" {
    fileinto "Support";
}

elsif header :contains "Subject" ["Develop", "Codereview"] {
    fileinto "Develop"
}

else {
    redirect "other.email@company.com";
    keep;
}

Finder shortcuts

2011-02-05T03:50:00.001-08:00

Today I realized that i don't know enough Finder shortcuts, here you are.

Command-A Select All Items
Command-C Copy Selected Items
Command-D Duplicate Selected Items
Command-F Search with Spotlight
Command-H Hide Window
Command-I Open Get Info (Property) Pane

Command-M Minimize Window
Command-N Open New Window
Command-O Open Selected Items
Command-V Paste Items
Command-W Close Finder Window

Command-1 View as Icons
Command-2 View as Lists
Command-3 View as Columns
Command-4 View as Coverflow

Command-Shift-A Go to Application Folder
Command-Shift-H Go to Home Folder
Command-Shift-N Create New Folder
Command-Option-O Open File and Close Finder

Creating a NPM package

2011-02-04T02:15:00.000-08:00

NPM is a package manager for node.

Creating packages with NPM is not difficult so here are the steps.

1. Creating the package.json

Here is an example

{
   "name": "packagename",
   "version": "0.0.1",
   "description": "Package description",
   "main": "package.js",
   "keywords": [
       "foursquare",
       "4sq"
   ],
   "repository" : {
       "type" : "git",
       "url" : "https://yikulju@github.com/yikulju/Foursquare-on-node.git"
    }  
}

2. Linking it with NPM

npm link

3. Publishing the package

First, you have to create a user in the repo.
npm adduser

Then you can publishing the package
npm publish

This is a good resource (Introduction to npm) but for some strange reason it was difficult to read, maybe the writing style.

Reload the browser when files change on OSX

2011-02-02T18:41:00.000-08:00

Web front-end development often looks like this, you change the code, which can be HTML, CSS, JavaScript, Ruby whatever and then you head over to the browser and reload it to see the changes.

This is not a big deal, but what if the browser could automatically does the reload.

My solution has three parts.

You can detect file change with Kicker.

Set the focus to the browser and reload it with AppleScript.

Set the focus back to your texteditor.

Let's combine these


kicker -e "osascript reload-browser.applescript;focus-textmate.applescript" FOLDER_TO_WATCH

In my case this looks like this


kicker -e "osascript ~/workspace/MacGyver/reload-browser.applescript;osascript ~/workspace/MacGyver/focus-textmate.applescript" src/

You can find the reload_browser.applescript here and the focus-textmate.applescript here.

Changing the default style in Kod

2011-01-28T00:27:00.000-08:00

Kod is a promising text editor for OS X.

One of the great things is that, you can style the editor with CSS.

mkdir ~/.kod
cp /Applications/Kod.app/Contents/Resources/style/default.css ~/.kod/

defaults write se.hunch.kod style/url ~/.kod/default.css

kod ~/.kod/default.css

then don't forget to reload the style in Kod, View menu/Reload style

Simulating mouse click on Snow Leopard

2011-01-27T01:07:00.000-08:00

After googling for 1 hour i came up with the following python script.


import sys
import time
from Quartz import *

def createMouseEvent(type, posx, posy):
 theEvent = CGEventCreateMouseEvent(None, type, (posx,posy), kCGMouseButtonLeft)
 CGEventPost(kCGHIDEventTap, theEvent)

if __name__ == '__main__':
 x = int(sys.argv[1])
 y = int(sys.argv[2])

 createMouseEvent(kCGEventLeftMouseDown, x, y);
 createMouseEvent(kCGEventLeftMouseUp, x, y);

Usage: python script.py 100 100
It'll move the mouse to (100, 100)

Here is the same script on github. click.py

I used the following sources
metapep's blogpost
pepijndevos's PyMouse
GeekOrgy's Python script
a stackoverflow entry

thanks!

Telling time in different timezones with bash on OSX

2011-01-25T22:47:00.001-08:00

You can use the TZ variable to affect the execution of date command.

Current time in Japan Standard Time (JST)
TZ=Asia/Tokyo date

Pacific Standard Time (PST)
TZ=America/Los_Angeles date

Eastern Standard Time (EST)
TZ=America/New_York date

Central Standard Time (CST)
TZ=America/Chicago date

Coordinated Universal Time (UTC) / Greenwich Mean Time (GMT)
TZ=Europe/London date

Central European Time (CET)
TZ=Europe/Budapest date

Here is how i use it. telltime.sh

Escaping special HTML characters in JSP

2011-01-25T18:24:00.000-08:00

If you have a string that contains special characters such as '&' and you want to display this in a JSP page, you may get a ' The content of elements must consist of well-formed character data or markup.'

This code will fail if linkParm contains a '&'


<a href="main.do${userBean.linkParm}">
    main link
</a>

The short answer is


<a href="main.do<c:out value='${userBean.linkParm}'/>">
    main link
</a>

This seems overkill, indeed.

EJS default escaping

2011-01-20T01:50:00.000-08:00

In EJS (Embedded JavaScript) escaping is a default behaviour.


// escape by default 
<%= VARIABLE_NAME %>

This can easily mess up a couple of things (including JSON, HTML rendering), luckily you can turn it off by using


// render out string 
<%- VARIABLE_NAME %>

Drop a MongoDB database from command line

2011-01-17T22:12:00.000-08:00

mongo DB_NAME --eval 'db.dropDatabase();'

Iterating through an array in bash

2011-01-06T23:13:00.000-08:00

locations=( Roppongi Shibuya Ebisu )

for name in ${locations[@]}
do
  echo $name
done

Generating random locations around a location

2011-01-06T00:47:00.000-08:00

Handy.


def generateLocation(startlat, startlon, maxdist):

 # converting them radians
 startlat *= pi / 180
 startlon *= pi / 180
 rand1 = random.random()
 rand2 = random.random()

 maxdist = maxdist / earthradius
 dist = acos(rand1*(cos(maxdist) - 1) + 1)
 brg = 2*pi*rand2

 lat = asin(sin(startlat)*cos(dist) + cos(startlat)*sin(dist)*cos(brg))
 lon = startlon + atan2(sin(brg)*sin(dist)*cos(startlat), cos(dist)-sin(startlat)*sin(lat))

 if lon < -pi:
  lon = lon + 2 * pi

 if lon > pi:
  lon = lon - 2 * pi

 lat *= 180 / pi
 lon *= 180 / pi

 return [lat, lon]

Turn off SpringSource Tool Suite Dashboard

2011-01-04T00:12:00.000-08:00

SpringSource Tool Suite 2.3.2 boots really slowly and it can be even slower if it opens the Dashboard at startup.
Lucky you can turn it off, not trivial though.

Dashboard has 4 tabs on the bottom (Dashboard, Knowledge Base, Extensions and Configuration).
At the Configuration tab there is a checkbox, Show On Startup.

Command-line tools on Mac OS X, Snow Leopard

2010-12-26T04:31:00.001-08:00

allmemory, fs_usage, fuser, latency, sar, sc_usage, spindump: Display various system usage statistics.

bless, disklabel, disktool, diskutil, drutil, fsck, hdiutil, pdisk: Create, identify, manage, and fix Mac OS X disks, file systems, and disk images.

ioreg, kextstat: Show device drivers and other kernel extensions in use.

mDNS, dns-sd: Test Bonjour service discovery with these diagnostic tools.

open: Invoke launch services on an arbitrary document or application as if doubleclicking it in the Finder.

pbcopy, pbpaste: Move data between stdin/stdout and the Mac OS X pasteboard.

say: Convert text to audio output or a file via Speech Synthesizer.

shasum: Compute or validate SHA message digests.

sips: Manipulate the format and color space of bitmap images (for example, rotate,

sw_vers, uname: Display Mac OS X version information.

syslog and logger: Send, view, and manage system log messages with these modern

xattr: List, display, set, and delete file system extended attributes

You can find more information on apple.com in this documentation.

snoop file opens on Snow Leopard

2010-12-21T22:57:00.000-08:00

Opensnoop tracks file opens.
sudo opensnoop

or you can watch only a process
sudo opensnoop -n Google Chrome

HTML5 heading elements

2010-12-21T19:51:00.000-08:00

"In HTML 4, the only way to create a document outline was with the <h1>–<h6> elements. If you only wanted one root node in your outline, you had to limit yourself to one <h1> in your markup.
But the HTML5 specification defines an algorithm for generating a document outline that incorporates the new semantic elements in HTML5.
The HTML5 algorithm says that an <article> element creates a new section, that is, a new node in the document outline. And in HTML5, each section can have its own <h1> element."

more of Pilgrimさん's Dive into HTML5
or check the outline of your document with the HTML5 Outliner

activemq and the java.io.EOFException: Chunk stream does not exist at page: 0

2010-12-21T18:50:00.000-08:00

If you start activemq and get an error like that


INFO | Scheduler using directory: activemq-data/localhost/scheduler
ERROR | Failed to start ActiveMQ JMS Message Broker. Reason: java.io.EOFException: Chunk stream does not exist at page: 0
java.io.EOFException: Chunk stream does not exist at page: 0

It means that there is something wrong with the scheduler.

If you don't use the built in persisten scheduler you can easily turn it off by changing the activemq.xml config file (/opt/local/share/java/activemq/conf/activemq.xml)

<broker xmlns="http://activemq.apache.org/schema/core" ....
to
<broker xmlns="http://activemq.apache.org/schema/core" schedulerSupport="false">

Open a new tab with AppleScript in Chrome

2010-12-20T23:19:00.003-08:00

tell application "Google Chrome"
 set myTab to make new tab at end of tabs of window 1
 set URL of myTab to "http://google.com"
end tell

more AppleScript Chrome goodies at http://laclefyoshi.blogspot.com/2010/10/google-chrome-ver.html

Get user id on a remote server

2010-12-20T22:23:00.000-08:00

you have to use SSH public/private key pairs to make this work.


#!/bin/bash
uid=`ssh <your.server> 'id -u'
echo $uid

more stuff here http://bashcurescancer.com/run_remote_commands_with_ssh.html

Google App Engine Development Console from command line

2010-12-20T01:08:00.000-08:00

When you develop on localhost the interactive console that Google provides is not convenient.
In my project I had to run few scripts in the console quite often, so instead of going to the interactive console all the time I could do it from command line.

This example executes the 'gen_pilot_data.py' script on the interactive console.


curl --data-urlencode "code=`cat src/gen_pilot_data.py`" http://localhost:8079/_ah/admin/interactive/execute

Please notice that you may have to the change the port number.

Latitude and longitude of cities

2010-12-19T18:45:00.000-08:00

http://www.getlatlon.com


 cities = [
  { 'name': 'Tokyo', 'lat': 35.6894875, 'lon': 139.6917064 },
  { 'name': 'Seoul', 'lat': 37.566535, 'lon': 126.9779692 },
  { 'name': 'Beijing', 'lat': 39.904214, 'lon': 116.407413 },
  { 'name': 'New Delhi', 'lat': 28.635308, 'lon': 77.22496 },
  { 'name': 'Moscow', 'lat': 55.755786, 'lon': 37.617633 },
  { 'name': 'Kiev', 'lat': 50.45, 'lon': 30.5233333 },
  { 'name': 'Budapest', 'lat': 47.4984056, 'lon': 19.0407578 },
  { 'name': 'Berlin', 'lat': 52.5234051, 'lon': 13.4113999 },

  { 'name': 'Paris', 'lat': 48.8566667, 'lon': 2.3509871 },
  { 'name': 'Madrid', 'lat': 40.4166909, 'lon': -3.7003454 },
  { 'name': 'New York', 'lat': 40.7143528, 'lon': -74.0059731 },

  { 'name': 'Mexico City', 'lat': 19.4270499, 'lon': -99.1275711 },
  { 'name': 'Honolulu', 'lat': 21.3069444, 'lon': -157.8583333 },

  { 'name': 'Sydney', 'lat': -33.8599722, 'lon': 151.2111111 },
  { 'name': 'Taipei', 'lat': 25.091075, 'lon': 121.5598345 }
 ]

Zoom to fit all markers with Google Maps V3

2010-12-17T02:22:00.000-08:00


// creating the map
var map = new google.maps.Map(document.getElementById("map_canvas"), {
  mapTypeId: google.maps.MapTypeId.ROADMAP
});

// latitude, longitude values
var latLons = [ { lat: 35.6453962, lon: 139.7117893 }, 
                           { lat: 35.645076, lon: 139.709183 }  ];

// this is the bounding box container
var bounds = new google.maps.LatLngBounds();

// iterating through the points
latLons.forEach( function (element, index, array) {

  var point = new google.maps.LatLng(element.lat,element.lon);
  
  // extending the bounding box
  bounds.extend(point);

  // creating the marker on the map
  var marker = new google.maps.Marker({
        position: point,
        map: map
    });
});

// zooming on the map
map.fitBounds(bounds);

Reload the browser with AppleScript

2010-12-14T19:03:00.000-08:00

AppleScript is a weird language but you still can do cool things with it.


tell application "Google Chrome"
        activate
end tell

tell application "System Events"
 tell process "Google Chrome"
  keystroke "r" using {command down}
 end tell
end tell

Please feel free to replace "Google Chrome" with your choice.

https://github.com/yikulju/MacGyver/blob/master/reload-browser.applescript

removing trailing whitespace with sed

2010-12-14T18:56:00.000-08:00


sed -i '' -e's/[ \t]*$//' $1

the full script can be found here
https://github.com/yikulju/MacGyver/blob/master/rwh.sh

is activemq running?

2010-11-30T21:53:00.000-08:00

Activemq is listening on the 61616 port so a simple telnet can help us.


telnet localhost 61616

If you get a response that starts with '?ActiveMQ?' it means that activemq is running.

Simulating cellular network bandwith

2010-11-30T18:39:00.000-08:00

To turn it on


sudo su
ipfw add pipe 1 src-port http
ipfw pipe 1 config delay 200 bw 700kbit/s

To reset


ipfw flush

Infinite blinking effect with jQuery

2010-11-29T22:34:00.001-08:00

I'm not sure this is the shortest way to do this but it works.


setInterval( function () {

 // this is the element you want to blink
 var box = $(".blinking_thing");
   
 if (box.data("fade") === 1) {
      box.fadeIn().data("fade", 2);
 } else {
      box.fadeOut().data("fade", 1);
 }
}, 800)

activemq and the java.io.EOFException: Chunk stream does not exist at page on broker start

2010-11-25T17:50:00.000-08:00

Deleting the activemq-data directory seems to be the only recovery solution (which is not an option in production)


rm -rf /opt/local/share/java/activemq/data

Changing the computer name on terminal

2010-11-18T23:05:00.000-08:00


sudo scutil --set HostName [NewMacComputerName]

Next flush the DNS cache on the Mac by entering the command:


dscacheutil -flushcache

Removing 1Password agent on Snow Leopard

2010-11-11T19:26:00.000-08:00

months after i uninstalled 1Password something was still spamming my log files.

It seemed like launchd has some problems, so i headed over one of the following folders


/System/Library/LaunchDaemons
/System/Library/LaunchAgents
/Library/LaunchDaemons
/Library/LaunchAgents
~/Library/LaunchAgents

I found this entry


ws.agile.1PasswordAgent.plist

let's delete it and refresh launchd


launchctl remove ws.agile.1PasswordAgent

and the problem has gone.

iTunes search with command f

2010-10-23T18:14:00.000-07:00

To use Command-F to get to the search field in iTunes you have to execute the following in Terminal.


defaults write com.apple.iTunes NSUserKeyEquivalents -dict-add "Target Search Field" "@F"

You have to restart iTunes to make it work.

gitignore and already tracked files

2010-10-19T00:59:00.000-07:00

If a file is already being tracked by Git, adding the file to .gitignore won’t stop Git from tracking it.

You’ll need to do


git rm --cached <file>

to keep the file in your tree and then ignore it.

SVG JavaScript Libraries

2010-10-17T22:45:00.000-07:00

SVG has been in development since 1999 and in 2010 we can say that all major modern web browsers except Microsoft Internet Explorer, support and render SVG markup directly. The Internet Explorer 9 beta supports SVG.

But dealing with SVG documents remained painful, don't despair there are JavaScript libraries to help.

Protovis
Great for data visualization.
It only works in browsers that have native SVG support.

Raphael
It's a good starter library, easy to do a LOT of things with SVG quickly. Well written and documented. Lots of examples and Demos. Very extensible architecture. Great with animation.

But note that there are ways of expressing things in SVG that are not possible in Raphael. There are no "groups". This implies that you can't implement layers of Coordinate Transfomations. Instead there is only one coordinate transform available.
If your design depends on nested coordinate transforms, Raphael is not for you.

It supports Firefox 3.0+, Safari 3.0+, Chrome 5.0+, Opera 9.5+ and Internet Explorer 6.0+.

jQuery SVG
Well written and documented. Lots of examples and demos. Supports most SVG elements, allows native access to elements easily.

It only works in browsers that have native SVG support.

SVG Web
It uses flash to render in non-SVG compliant browsers.

List open ports on Mac OS X

2010-10-04T19:05:00.000-07:00

sudo lsof -i -P | grep -i "listen"

FDTG Principles for Developers

2010-09-20T19:11:00.000-07:00

this is a small reminder for me no to forget these principles.

Flexibility
Be ready to change your plans when they’re not working the way you expected; don’t count on things remaining stable.

Decentralization
Centralized systems look strong, but when they fail, they fail catastrophically.

Transparency
Don’t hide your systems; transparency makes it easier to figure out where a problem may lie. Share your plans and preparations, and listen when people point out flaws.

Graceful Failure
Failure happens, so make sure that a failure state won’t make things worse than they are already.

HTML Comments as strings

2010-08-23T10:03:00.000-07:00

Reading HTML comments from a DOM tree with JavaScript is easy.


var nodes = document.body.childNodes,
    comments = [];

for (var i = 0; i < nodes.length; i++) {

    // if the nodeType is 8
    if (nodes[i].nodeType == 8) {
          
          // this is a comment
          comments.push(nodes[i]);
    }
}

Let's say that the comments array is not empty, so the type of comments[0] is a Comment. That's great but how can you read its content?

This is what the W3C DOM-Level-1 spec says. It implements the Comment interface.


interface Comment : CharacterData {
};

This does not really help us but don't despair. It also implements the Node interface.


  ...
  readonly attribute  DOMString            nodeName;
           attribute  DOMString            nodeValue;
  ...

Yes, it's read-only but you can get the comment as a string by using its nodeValue.


comments[0].nodeValue

W3C DOM-Level 3 specifies something called textContent. This can also do the job, you can read about them here, textContent vs. innerText